Gas sensors play an important role in safety technology, for example for the detection of carbon monoxide gas, hydrocarbons, or nitrogen oxides, for measuring motor vehicle emissions, or for monitoring the air quality of buildings.
European Patent No. EP 1192452 B1 describes a chemical sensor that is made up of a substrate on which is applied a heating element on which an electrical insulation layer is in turn applied. Located on the insulation layer is a sensor element made of metal oxide, to which an electrical signal can be transmitted via conductor paths, as well as a metal oxide layer.
Gas sensors of this kind manufactured from droplet-capable or dispensable materials, or from materials for thick-layer processes, have the advantage of high reproducibility as compared with the materials of sensors manufactured using many thin-layer processes or from nanoparticle inks. In order to obtain several contactable metal oxide layers using droplet or thick-layer processes, however, they must be applied next to one another, with the result that miniaturization of the gas sensors is not possible or is restricted.